Figure 6.
p53-responsive gene expression is intact in p53-inducible impd transfectants. Five micrograms of total cytoplasmic RNA isolated from control, p53-inducible, vector transfectant (tC-2, tC-4), and impd transfectant (tI-1, tI-3) cells, grown for 2 d under standard conditions in Zn-free growth medium (−) or medium containing 75 μM ZnCl2 (+; wild-type p53-inducing condition), were examined by Northern blot analysis with sequential hybridization to specific DNA probes to detect the indicated mRNAs as described in MATERIALS AND METHODS. The faster mobility IMPD mRNA derives from the endogenous mouse impd gene (endo), and the slower mobility IMPD mRNA derives from the stably transfected hamster impd cDNA (trans).